Theory of resonance energy transfer involving nanocrystals: the role of high multipoles

TL;DR

This paper develops a theoretical model for fluorescence resonance energy transfer (FRET) between semiconductor nanocrystal quantum dots, emphasizing the significance of high multipole interactions like dipole-quadrupole coupling.

Contribution

It introduces a comprehensive theory incorporating high multipole effects into FRET between nanocrystals, relating the transfer rate to measurable physical parameters.

Findings

High multipole interactions significantly influence FRET rates.

The model accounts for nanocrystal size, confinement regimes, and dielectric properties.

Dipole-quadrupole coupling can dominate under certain conditions.

Abstract

A theory for the fluorescence resonance energy transfer (FRET) between a pair of semiconducting nanocrystal quantum dots is developed. Two types of donor-acceptor couplings for the FRET rate are described: dipole-dipole (d-d) and the dipole-quadrupole (d-q) coupling. The theory builds on a simple effective mass model which is used to relate the FRET rate to measureable quantities such as the nanocrystal size, fundamental gap, effective mass, exciton radius and dielectric constant. We discuss the relative contribution to the FRET rate of the different multipole terms, the role of strong to weak confinement limits, and the effects of nanocrystal siz-es.